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(No Model.)

(5l/@Humacao M. RAUGHTIGAN.

DASH POT.

Patented Aug. 26, 1890.

mi QMOUQX Rmmcgtgomh NTTED STATES PATENT CEEICE.

MICHAEL RAUGHTIGAN, OENORWICH, CONNECTICUT, ASSIGNOR OE ONE- HALE TOFRANK C. TURNER, OF SAME PLACE.

DASH-POT.

SPECIFICATION forming part of Letters Patent No. 434,951, dated August26, 1890.

Application filed J'uly 2, 1890. Serial No. 357|569- (N0 model-l To allwhom, it may concern:

Be it known that I, MICHAEL RAUGHTIGAN, a citizen of the United States,residing at Norwich, in the county of New London and State ofConnecticut, have invented a certain new and useful Improvement inDash-Pots, which improvement is fully set forth and described in thefollowing specification, reference being had to the accompanying sheetof drawings, in which- Figure 1 is a side elevai ion of a dash-pot of myimproved construction, and Fig. 2 a longitudinal sectional view of thesame.

This invention is in so-called dash-pots used for cushioning variousforms of mechanisms by means of a liquid confined within a suitablereceptacle and cont-rolled by a piston or plunger being connected to andadapted to niovemfith an operative part of the machine with which saidcomplete dash-pot is connected. Dash-pots of this class have been usedcommonly and are valuable aids in current-regulating mechanisms fordynamo-elec tric machines, a familiar example of such adaptation beingseen in United States Patent No. 238,315, issued March 1, 1881, thedashpot being therein utilized to prevent any too sudden movement of thearmature.

The immediate obj ect of mypresent invention is to provide a means ofcommunication between the adjacent chambers of the dashpot to the endthat the flow of liquid through or past the piston may be more perfectlycontrolled than heretofore; also, to provide a form of regulatingmechanism that may be adjusted, if desired, without stopping the dynamoor other machine to which the dash-pot is connected.

Referring to the annexed drawingt, the let ter a indicates thecylindrical shell of my dash-pot, having a screw-cap b at one end and aperforated lug c at' the opposite end, by means of which said cylindermay be connected to the machine.

d indicates a piston or plunger iitted to slide in the cylinder a, saidpiston being attached to a rod e, that projects outward through thescrew-cap b and terminates in a lug-fastening e', substantially like thedescribed lugfastening c.

In the lower end o f the piston-rod c is bored a vertical hole f, whichleads upward and counectswith lateral openings g, as shown in Fig. 2,thus providing a free and unobstructed passage between the compartmentsof cylinder d above and below the piston.

The piston-rod e is screw-threaded th roughout a portion of its length,and on said rod is an internally-threaded tubular section t', having atAits upper end a iianged head or thumb piece la, that may be used as anoperatinghandle to rotate the tubular section e' on the piston-rod e.The lower end of said tubular section is preferably formed as anenlarged head j, which abuts the piston d when the tubez' is screweddownward on the pistonrode and forms a tight valve to prevent thepassage of liquid through the openings f and g. By varying the height oftube ft' on the piston-rod e, more or less of holes g may be exposed andthe flow of 'liquid through said holes controlled. The head j on tube c'may be omitted; but I prefer the form shown in the drawings, as itinsures a more perfect tit with the piston d. The resistance of theliquid when the dash-pot is in use is of course proportionate .to theease with which said liquid may escape under pressure, and it will bereadily understood that the valve mechanism above described allows theoperator in charge to vary the degree of resistance as circumstances orjudgment may direct.

Having described my invention, I claim- The combination, in a dash-pot,of an inclosing shell, piston, and piston-rod having a centrallongitudinal opening with lateral openings, as set forth, and a tubefitted to move longitudinally on said piston-rod to cover or expose saidlateral openings, for the purpose specified.

MICHAEL RAUGIAITIGAN.

Witnesses:

FRANK H. ALLEN, ALONZO M. LUTHER.

